1550s, from French sultan "ruler of Turkey" (16c.), ultimately from Arabic (Semitic) sultan "ruler, prince, monarch, king, queen," originally "power, dominion." According to Klein's sources, this is from Aramaic shultana "power," from shelet "have power." Earlier English word was soldan, soudan (c. 1300), used indiscriminately of Muslim rulers and sovereigns, from Old French souldan, soudan, from Medieval Latin sultanus. Related: Sultanic.
Sultan of Egypt and Syria from 1174-93, target of the Third Crusade (1189-1192); in full Salah-ad-din Yusuf ibn-Ayyub (1137-1193).
1580s, in reference to Muslim lands, "the part of the dwelling where the women are secluded," also the name of a former palace of the sultan in Istanbul, which contained his harem; from Italian seraglio, alteration of Turkish saray "palace, court," from Persian sara'i "palace, inn." This is from the Iranian base *thraya- "to protect" (source also of Avestan thrayeinti "they protect"), from PIE *tra-, a variant form of the root *tere- (2) "cross over, pass through, overcome."
The Italian word probably reflects folk etymology influence of serraglio "enclosure, cage," from Medieval Latin serraculum "bung, stopper" (see serried). Sometimes in English in early use serail, via French sérail, which is from the Italian word. The meaning "inmates of a harem" is attested by 1630s.
In English, the Ottoman sultan was the Grand Turk (late 15c.), and the Turk was used collectively for the Turkish people or for Ottoman power (late 15c.). From 14c. and especially 16c.-18c. Turk could mean "a Muslim," reflecting the Turkish political power's status in the Western mind as the Muslim nation par excellence. Hence Turkery "Islam" (1580s); turn Turk "convert to Islam."
Meaning "person of Irish descent" is first recorded 1914 in U.S., apparently originating among Irish-Americans; of unknown origin (Irish torc "boar, hog" has been suggested). Young Turk (1908) was a member of an early 20c. political group in the Ottoman Empire that sought rejuvenation of the Turkish nation. Turkish bath is attested from 1640s; Turkish delight from 1877.